Here is what I would do.
Drive up to the Lakes on Tuesday then Ride Nan Beild on the Wednesday- it is close to the motorway and if worked into a loop will suit a red grade rider.
Then drive north to Ben Lomond to ride that on Thursday. A perfect big mountain for that level.of rider with stunning, stunning views and an excellent trail.
Finally I would head to the Devil’s Staircase in Glencoe. Again it is on your way and an excellent bit of trail that’ll be enjoyable for both of you- exciting enough for a very good rider and not so tough that a red grade rider will be pushing.
I’d not bother with the 7 stanes if you are here as a one off or rare trip, they are excellent but there is too much good natural riding to squeeze in. I would, however, heartily recommend driving to Laggan from Fort William on the Saturday morning or Monday and riding the trail centre there. It has the best trails of an trail centre in the UK, although they are short the quality is very high and it’s close to fort bill.